Brain expansion: different theories about rapid expansion (Evolution)

by dhw, Monday, August 17, 2020, 09:27 (432 days ago) @ David Turell

I'm combining the expansion threads, and it won't hurt to move to a different heading.

DAVID: A mechanism put in the brain by God when He expanded it as sapiens appeared by His design.

dhw: This is a change from your previous agreement that our predecessors would also have had a mechanism for complexification.

DAVID: My statement doesn't say 'new' mechanism. I've always said previous brains had complexification.

Your statement says he put in the mechanism when he expanded it to sapiens size. That makes it new.

DAVID: Took another look at current articles:

The quotes tell us that approx. 35,000 years ago sapiens’ brain gradually changed its shape from elongated to round in order to accommodate parietal and cerebella bulging, and this process ran parallel to the gradual emergence of “behavioural modernity”.

dhw: Do you think your God stepped in to do the bulging before sapiens came up with his modern ideas, or do you think it was implementation of the ideas that caused the bulging? I am opting decisively for the latter. And I am proposing that if new behaviour, ideas, requirements can cause the brain to change its shape, to complexify, to expand in certain areas, the same process may explain the expansion of earlier brains.

DAVID: The changing brain shape is certainly due to complexification. The bony shape change is due in part to simple adaptation. The infant and child skull plates are soft and held together by fibrous material with fusion occurring in late adolescence. God not involved.

Thank you. My point once again is that if God was not involved in the changing shape of the brain and skull, its complexifications and its minor expansions, there is every reason to believe that the same mechanism for shape-changing, complexification and expansion would have caused the expansion of earlier homo and hominid brains. We can of course allow for God as the inventor of the mechanism, but there was no need for him to dabble: the mechanism was perfectly capable of doing its own restructuring.

Rapid expansion theory:

QUOTES: "The response used by scientists to explain the evolution of the human brain involves a "fast evolution" scheme. Researchers at the Howard Hughes Medical Institute concluded that the human brain evolved very rapidly. Their research led them to believe that there was considerable "selection pressure" to evolve the brain into a larger, stronger unit. As human society became more sophisticated, the advantage of a larger brain became more pronounced. This caused the evolutionary process to accelerate, resulting in a quick progression to modern man. (David’s bold)

…there are plenty of reasons given for why a larger, stronger brain is useful, yet no actual biological or physical explanation for how it occurred.”

"Even the terminology used by scientists to explain the evolution of the human brain sounds anything but random: The homo sapiens brain evolution was a "special event." Rapid evolution was "needed." The brain evolved "in preparation" for our complex social structure. Even those dedicated to a random, naturalistic explanation for life cannot avoid using terminology that implies purpose, intent, and intelligence."

David: I have bolded thoughts I do not agree with. Real socialization and civilization appeared long after the 315,000 year-old Moroccan/sapiens….

I’ve omitted the section on the eye as it is the above quotes that deal with our own discussion. I’m surprised you didn’t bold the last quote, as it clearly supports your own theory. However, we should note firstly that the authors point out as I have done repeatedly that nobody knows how the brain expanded, and they only hint at a possible divine intervention at the very end. Secondly, in their brief article, they fail to mention the processes of complexification and minor expansion which we know are the brain’s responses to new requirements. The “fast evolution” of the brain they refer to is not so extraordinary if you realize that every new idea or requirement or adaptation to new conditions causes the brain to change. It is not, then, the "fast" complexification or development or evolution of the brain that is so extraordinary, but the number of new ideas etc. that must have caused the changes that took place during the last 35,000 years. The enlargement itself - let’s say 315,000 years ago – remains unexplained.

As regards the final comment, I think we both agree that “random” is out of the question (apart from when you get lost in your new errors theory), but a naturalistic explanation is perfectly possible if we accept that purpose, intent and intelligence may be involved at the cellular level. And this does not preclude God: if he exists, he would have invented the intelligent cell whose activities enable all organs and organisms to adjust to new requirements and possibly even to provide all the innovations that have led not only to the human brain but also to all the species and econiches and natural wonders that have come and gone throughout life’s history.

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